Fungus Lacazia Loboi Research Articles

P308 Jorge lobo's disease in brazil: a new recognized reservoir?

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMLobomycosis (lacaziosis) is a chronic subcutaneous disease caused by the uncultivated fungus Lacazia loboi. The disease was first described in 1931 by Jorge Lobo in Brazil and has been reported in South and Central America. Lobomycosis is a rare disease that affects certain geographic regions, mainly in countries of low socioeconomic status, but its prevalence among indigenous people in Brazil is exceptionally high. The state of Maranhão is located in the northeast region of the country and there are rare clinical reports of imported cases of the disease in our region. This is the first published series of autochthonous cases of lacaziosis in Maranhão.ObjectiveTo describe seven cases of Lacazia loboi infections in immunocompetent patients in an endemic area for other subcutaneous mycoses.MethodsWe retrospectively reviewed the medical records of all patients who developed Jorge Lobo's diseases in a new area recognized as a potential environment reservoir. An incident case was defined as a patient who developed proven lacaziosis based on the presence of topical fungal elements in the tissue on histopathology or mycologic direct exam. Epidemiological and clinical data of all cases of lacaziosis were collected using a standard clinical form.ResultsIn the period from 2000 to 2021, seven patients were identified. All cases were diagnosed by histopathology and direct mycological examination of the lesions. A total of 6 out of 7 (85.7%) patients were men and the mean age was 57 years (52-70 years). The median time between onset of infection symptoms and diagnosis was ˃2 years in 6 patients, with 15 years of symptoms duration in patient 7. All patients reported having worked with agricultural activities before. A total of 50% of patients were diagnosed with localized lesions and the other half with disseminated lesions. Subcutaneous lesions involved the upper limbs (4/6; 66.6%), ears (2/6; 33.3%), lower limbs (1/6; 16.6%), and trunk (1/6; 16.6%). All patients exhibited nodules as a dominant pattern of skin lesion, sometimes coalescing with the tumor's appearance. Regarding treatment, a combination of itraconazole and clofazimine therapy was added to all patients. Surgical excision was possible only in 2 episodes due to the limited availability of this procedure at the site. Cure was documented in 2 cases, with no recurrence to date.ConclusionThe present series represents the first and largest collection of case studies of lacaziosis in Maranhão state, with all cases classified as autochthonous. Lacaziosis involves mainly adult males with different occupational risks such as agricultural labor, and other workers exposed to contaminated soil and plant materials. Few data are available to support suggested therapy with itraconazole and clofazime. Excision surgery is important for treatment due to the absence of clinical trials in the medical literature. Epidemiological surveillance studies of new cases of lacasiozis in Maranhão are important for mapping this new reservoir and developing public policies for diagnosis and treatment.

Comparative effect of osmium tetroxide and ruthenium tetroxide on Lacazia loboi ultrastructure.

Lobomycosis is a skin infection produced by the fungus Lacazia loboi, which mainly affects some indigenous and afro-descendant populations in Tropical America. We previously reported the comparative effect of osmium tetroxide (OsO4 ) and ruthenium tetroxide (RuO4 ) in the electron microscopy (EM) of other related microorganisms. The objective of this study is to compare the effect of postfixation with OsO4 and RuO4 in the ultrastructure of L. loboi yeasts. Skin biopsies on patients diagnosed with lobomycosis were fixed in glutaraldehyde at 3% and postfixed in the following solutions: (a) 1% OsO4 , (b) 0.2% RuO4 , and (c) OsO4 at 1% followed by RuO4 at 0.2%. They were then processed using the conventional method for EM. Unlike OsO4, the treatment with RuO4 revealed different shades of gray and electron dense bands in the cell wall and other cell components of L. loboi. The most notable finding was the presence of radial filamentous structures around the yeast, which made the image look like the sun. Postfixation with RuO4 revealed ultrastructural details that had not been previously reported for L loboi. The combined use of OsO4 and RuO4 in EM of microorganisms with cell walls can be useful to evaluate the effect of microbicide substances.

Lacaziosis: immunohistochemical evaluation of elements of the humoral response in cutaneous lesions.

ABSTRACTLacaziosis is a cutaneous mycosis caused by the fungus Lacazia loboi, described in different countries of Latin America and prevalent in the Amazon region. The ineffective immune response against the agent seems to be related to a Th2 pattern of cytokines. There are few reports exploring elements of the humoral response in these lesions. Our aim was to investigate some elements focusing on B cells, plasma cells and local expression of IgG and IgM antibodies. Forty skin biopsies of lower limbs were selected. The diagnosis of lacaziosis was based on direct mycological examination and histological analysis. The visualization of fungal cells was improved by using Gridley’s staining. An immunohistochemical protocol was performed to detect the expression of B cells, plasma cells, IgG and IgM. A double staining was performed to explore the presence of yeasts in the cytoplasm of keratinocytes, using an anti-AE1 AE3 antibody over Gridley’s staining. The inflammatory infiltrate consisted of macrophages, multinucleated giant cells, lymphocytes, and fibrosis. Fungal cells were frequent in the stratum corneum and in both, the dermis and, in 50% of the specimens, also in the epidermis. Cells expressing IgG were more abundant when compared to cells expressing IgM. B cells and the presence of IgG might indicate that the humoral response promotes a Th2 immune response resulting in an anti-inflammatory phenotype. Our results lead us to suggest a possible role of B cells and immunoglobulins in the mechanisms of lacaziosis pathogenesis.

The cytotoxic T cells may contribute to thein situimmune response in Jorge Lobo's Disease human lesions

Jorge Lobo's Disease (JLD) is a cutaneous chronic granulomatous disease caused by the pathogenic fungus Lacazia loboi. It is characterized by a granulomatous reaction with multinucleated giant cells and high number of fungal cells. In order to contribute to the comprehension of immune mechanisms in JLD human lesions, we studied the cytotoxic immune response, focusing on TCD8+ and NK cells, and granzyme B. Forty skin biopsies of lower limbs were selected and an immunohistochemistry protocol was developed to detect CD8+ T cells, NK cells and Granzyme B. In order to compare the cellular populations, we also performed a protocol to visualize TCD4+ cells. Immunolabeled cells were quantified in nine randomized fields in the dermis. Lesions were characterized by inflammatory infiltrate of macrophages, lymphocytes, epithelioid and multinucleated giant cells with intense number of fungal forms. There was a prevalence of CD8 over CD4 cells, followed by NK cells. Our results suggest that in JLD the cytotoxic immune response could represent another important mechanism to control Lacazia loboi infection. We may suggest that, although CD4+ T cells are essential for host defense in JLD, CD8+ T cells could play a role in the elimination of the fungus.

Analysis of Immune Response Markers in Jorge Lobo's Disease Lesions Suggests the Occurrence of Mixed T Helper Responses with the Dominance of Regulatory T Cell Activity.

Jorge Lobo’s disease (JLD) is a chronic infection that affects the skin and subcutaneous tissues. Its etiologic agent is the fungus Lacazia loboi. Lesions are classified as localized, multifocal, or disseminated, depending on their location. Early diagnosis and the surgical removal of lesions are the best therapeutic options currently available for JLD. The few studies that evaluate the immunological response of JLD patients show a predominance of Th2 response, as well as a high frequency of TGF-β and IL-10 positive cells in the lesions; however, the overall immunological status of the lesions in terms of their T cell phenotype has yet to be determined. Therefore, the objective of this study was to evaluate the pattern of Th1, Th2, Th17 and regulatory T cell (Treg) markers mRNA in JLD patients by means of real-time PCR. Biopsies of JLD lesions (N = 102) were classified according to their clinical and histopathological features and then analyzed using real-time PCR in order to determine the expression levels of TGF-β1, FoxP3, CTLA4, IKZF2, IL-10, T-bet, IFN-γ, GATA3, IL-4, IL-5, IL-13, IL-33, RORC, IL-17A, IL-17F, and IL-22 and to compare these levels to those of healthy control skin (N = 12). The results showed an increased expression of FoxP3, CTLA4, TGF-β1, IL-10, T-bet, IL-17F, and IL-17A in lesions, while GATA3 and IL-4 levels were found to be lower in diseased skin than in the control group. When the clinical forms were compared, TGF-β1 was found to be highly expressed in patients with a single localized lesion while IL-5 and IL-17A levels were higher in patients with multiple/disseminated lesions. These results demonstrate the occurrence of mixed T helper responses and suggest the dominance of regulatory T cell activity, which could inhibit Th-dependent protective responses to intracellular fungi such as L. loboi. Therefore, Tregs may play a key role in JLD pathogenesis.

DNA damage in BALB/c mice infected with Lacazia loboi and its relation to nutritional status.

BackgroundJorge Lobo’s disease, also known as lacaziosis, is a cutaneous-subcutaneous mycosis with chronic evolution. It is caused by the fungus Lacazia loboi. Herein we report a study that relates the genotoxicity caused by L. loboi in isogenic mice with nutritional status, through a normal or restricted diet.MethodsDNA damage was assessed in the peripheral blood by the comet assay (tail intensity).ResultsThe results for leukocytes showed increases in the mean tail intensity in mice under dietary restriction, in infected mice under dietary restriction and in infected mice ingesting a normal diet.ConclusionThese results indicate that dietary restriction and L. loboi infection may increase DNA damage levels in mice, as detected by the comet assay.

Jorge Lobo's disease: a case of keloidal blastomycosis (lobomycosis) in a nonendemic area.

Lobomycosis or lacaziosis is a chronic subcutaneous fungal infection, caused by the fungus Lacazia loboi, which is phylogenetically related to Coccidioides, Blastomyces, Histoplasma, and Paracoccidioides. The disease was first recognized in 1931 by Jorge Lobo, who found the disease to be a keloidal blastomycosis and named it Jorge Lobo's disease. This case was perplexing initially as this fungal infection is very uncommon in the USA. However, with the ever-increasing frequency of international travel, many more cases of lobomycosis have been diagnosed in areas of nonendemicity, such as the USA, Europe, and South Africa. The clinical histories of such imported fungal infections often illustrate their long latency periods. In lobomycosis, the onset of the disease is usually insidious and often difficult to document. We describe a case of a New York resident who presented with multiple skin nodules over both his arms and forearms, and was subsequently diagnosed with Jorge Lobo's disease. The case, diagnosis, histopathologic findings, complication, and management of this rare clinical disease are discussed.

DOENÇA DE JORGE LOBO: RELATO DE CASO E REVISÃO DE LITERATURA

Introduction and objectives: Jorge Lobo’s disease is a rare chronic disease caused by the fungus Lacazia loboi, characterized by keloid lesions on the skin. The objective is to perform a review of the literature and report the first case of Jorge Lobo’s disease treated at the University Hospital Cassiano Antônio Moraes (HUCAM). Materials and methods: The study data were obtained retrospectively from the analysis and systematic review of the medical records of a patient with Jorge Lobo’s diseaseidentified in HUCAM. Case Report: A male patient aged 37 years was referred to HUCAM in April 2010 presenting with keloid lesions and a previous diagnosis of lobomycosis by histopathology examination. On December 2011 a partial removal of the lesions with grafting was performed. Three months later, there was recurrence of lobomycosis on the grafted tissue. In June 2012 drug treatment with clofazimine associated with fluconazole was started. The lack of satisfactory clinical responseafter two months meant that the disease was considered beyond cure. Discussion and literature review: lobomycosis is an endemic disease in the brazilian Amazon and other humid tropical areas of Central and South America, and its transmission occurs by inoculation of the fungus through breaks in the skin. Diagnosis is made by clinical examination and histopathologiy or cytology The choice of therapy varies with the extent of lesions. However, none of the therapies described in the literature is fully effective. Conclusion: In this case, the two main therapeutic approaches failed, andthe disease was considered incurable.

Lobomycosis: A case from Southeastern Europe and review of the literature

Lobomycosis, also known as Jorge Lobo's disease, represents a rare chronic subcutaneous mycosis caused by the fungus Lacazia loboi, an organism that is found within lesions but has not been cultured to date. The natural reservoir of L. loboi is unknown but it is believed to be aquatic, or associated with soil and vegetation. More than 550 human cases have been reported, especially in patients with a history of travel or residence in endemic areas (Central and South America, particularly Brazil) or in communities along rivers. We describe a 64-year-old Greek female farmer living in a coastal region, who presented with an erythematous plaque on her left inner thigh resembling a keloid. The diagnosis was based on the triad: 1) absence of fungal growth in cultures, 2) positive direct microscopic examination of the lesion and 3) histopathology, all consistent with lobomycosis. Particularly, skin biopsy showed deep cutaneous fungal infection with granulomatous reaction. Fungal cells were found inside giant cells. The fungi were thick-walled with some budding, isolated or in short chains. Dermal fibrosis was present. Our patient had a medical history of common variable immunodeficiency but no history of travel to South or Central America. She probably acquired this rare infection by injury during her agricultural works. Our case represents probably the first documented case of human lobomycosis in Southeastern Europe. This case is unusual due to the rarity of lobomycosis in Mediterranean countries, particularly in Southeastern Europe.

Lacaziosis in bottlenose dolphins Tursiops truncatus along the coastal Atlantic Ocean, Florida, USA

This study represents the first systematic study of lacaziosis (lobomycosis) in bottlenose dolphins Tursiops truncatus in the Atlantic Ocean along the east-central coast of Florida, USA. Lacaziosis is a chronic infection of the skin caused by the fungus Lacazia loboi, which affects only dolphins and humans. Previous studies have shown a high prevalence (6.8 to 12.0%) of lacaziosis in resident dolphins from the adjacent Indian River Lagoon Estuary (IRL), where the disease is endemic. We examined the prevalence of lacaziosis in this coastal area using photo-identification data collected between 2002 and 2008 to determine the prevalence of lacaziosis in coastal dolphins using photographic methodology shown to have high sensitivity and specificity in prior research. The prevalence of skin lesions compatible with lacaziosis estimated from photographic data was 2.1% (6/284), approximately 3 times lower than that described for the estuarine population using similar methods. To exclude potential bias introduced by differences in study duration and survey effort among areas, an 18 mo period when effort was most equal (January 2006 to June 2007) was chosen for statistical comparison. The prevalence of lacaziosis estimated from photographic data was significantly lower (3.8%: n = 6/160) in the Atlantic Ocean compared to the IRL (12.0%: n = 20/167) (risk ratio = 3.19, 95% CI 1.32 to 7.75, p < 0.01 by chi-square analysis). The lower prevalence of lacaziosis in dolphins found in the Atlantic Ocean and the overall lack of movement of dolphins between these habitats suggests that environmental conditions within the estuary may favor viability of L. loboi, and/or that immune compromise in resident estuarine dolphins is a precursor to the disease.

Immunohistochemical study of Langerhans cells in cutaneous lesions of the Jorge Lobo's disease

Jorge Lobo's disease is a chronic infection caused by the fungus Lacazia loboi endemic in South America. The infection is characterized by the appearance of parakeloidal, ulcerated or verrucous nodular or plaque-like cutaneous lesions. The histopathological aspect is characterized by poorly organized granulomas with histiocytes and multinucleated giant cells. Little is known about local immune response in lobomycosis skin lesions. Thirty-three skin biopsies from patients with Jorge Lobo's disease were selected from Ambulatory of Dermatology, UFPA. The control group was constituted by ten biopsies from normal skin. Langerhans cells were identified by immunohistochemistry using anti-CD1a antibody (Serotec). The number of positive cells was statistically analyzed. Langerhans cells were visualized along the epidermis in biopsies from Jorge Lobo's disease and the morphology and the number of Langerhans cells did not differ from normal skin (p>0.05). In Jorge Lobo's disease, this cell population probably presents some escape mechanism of the local immune system to evade the antigen presentation by those cells.

Lobomycosis. Literature Review and Future Perspectives

Lobomycosis is a cutaneous infection of tropical and subtropical regions caused by the fungus Lacazia loboi, which still has a controversial taxonomical position . The first description of the disease and fungus was made in 1930 by Jorge Lobo. It is a chronic disease with predominance of lesions similar to keloids, in exposed areas, limited to skin and semimucosa. There is no systemic involvement and patients maintain a good general health. Diagnosis is confirmed by direct or histopathologic exam and, until present, the fungus has not been cultivated. Surgery is the treatment of choice for isolated lesions, but there are frequent recurrences. Good therapeutic responses have been reported with clofazimine, with or without itraconazole, and with 5-fluorocytosine. This disease should be recognized by dermatologists worldwide because, although restricted to the Amazon region, it has been observed in other locations. Research development and achievement of new knowledge in molecular biology and genetic engineering of lobomycosis are of utmost importance because they may, in the future, lead to the culture of the fungus in the laboratory and to a better understanding of its pathogenesis, transmission mechanism, and new methods of diagnosis, prevention and treatment.

Lacaziose simulando hanseníase dimorfa tuberculóide

Lacaziose é infecção crônica causada pelo fungo Lacazia loboi, originalmente descrita por Jorge Lobo (1931) em paciente oriundo da Amazônia brasileira. Manifesta-se, sobretudo, por lesões cutâneas queloidiformes. Relata-se o caso de paciente com placa eritêmato-violácea, cuja hipótese diagnóstica inicial foi de hanseníase dimorfa tuberculóide, doença também endêmica na região amazônica. Ressalta-se a importância da inclusão de formas paucibacilares de hanseníase no diagnóstico diferencial da lacaziose.

In vitro and in situ activation of the complement system by the fungus Lacazia loboi

Since there are no studies evaluating the participation of the complement system (CS) in Jorge Lobo's disease and its activity on the fungus Lacazia loboi, we carried out the present investigation. Fungal cells with a viability index of 48% were obtained from the footpads of BALB/c mice and incubated with a pool of inactivated serum from patients with the mycosis or with sterile saline for 30 min at 37 masculineC. Next, the tubes were incubated for 2 h with a pool of noninactivated AB+ serum, inactivated serum, serum diluted in EGTA-MgCl2, and serum diluted in EDTA. The viability of L. loboi was evaluated and the fungal suspension was cytocentrifuged. The slides were submitted to immunofluorescence staining using human anti-C3 antibody. The results revealed that 98% of the fungi activated the CS by the alternative pathway and no significant difference in L. loboi viability was observed after CS activation. In parallel, frozen histological sections from 11 patients were analyzed regarding the presence of C3 and IgG by immunofluorescence staining. C3 and IgG deposits were observed in the fungal wall of 100% and 91% of the lesions evaluated, respectively. The results suggest that the CS and immunoglobulins may contribute to the defense mechanisms of the host against L. loboi.

Distribuição fenotípica e a freqüência genotípica do sistema sangüíneo Duffy em pacientes com a doença de Jorge Lobo

A doenca de Jorge Lobo e uma micose cutânea e subcutânea de evolucao cronica, causada pelo Lacazia loboi. Os mecanismos envolvidos na suscetibilidade/resistencia do hospedeiro frente ao agente nao estao ainda elucidados, dentre eles encontra-se a constituicao genetica. Portanto, o objetivo deste trabalho e avaliar a distribuicao fenotipica do grupo sanguineo Duffy em pacientes com doenca de Jorge Lobo e calcular suas frequencias genicas. Foram analisados 21 pacientes, 13 caucasoides e oito mesticos (tipo moreno claro), provenientes do estado do Acre, e 44 individuos, nao acometidos por esta doenca, habitantes da cidade de Rio Branco (AC), como grupo controle. O fenotipo Duffy foi definido pela presenca dos antigenos nas hemacias pela reacao de aglutinacao dos eritrocitos com anti-soros anti-Fya e anti-Fyb incubando-se a 37oC e aplicando-se o teste da antiglobulina humana. Os resultados mostram que a distribuicao fenotipica do sistema Duffy nos pacientes difere significativamente daquela observada nos controles, pela alta frequencia de individuos com fenotipo Fy(a-b-). Observa-se claramente que os pacientes apresentam maior frequencia do alelo FY e menor do alelo FYA do que os controles. O alelo FYB (nao inclui os alelos que nao sao expressos) tem praticamente a mesma frequencia nos dois grupos. Com relacao a comparacao entre distribuicao do grupo sanguineo Duffy com as formas clinicas, sugere maior numero de pacientes com forma localizada da doenca de Jorge Lobo apresentando um predominio do fenotipo Fy(a-b+) seguido do fenotipo Fy(a-b-) e inexistencia do fenotipo Fy(a+b-). Por outro lado, temos a forma disseminada com maior incidencia de fenotipo Fy(a+b-). A forma multifocal foi menos expressiva. Desse modo, podemos inferir uma provavel prevalencia de fenotipo Duffy negativo na regiao por nos estudada e os poucos dados disponiveis ate o momento tornam clara a necessidade de elaborar tabelas de frequencias fenotipicas para a populacao acometida pela doenca de Jorge Lobo, bem como realizar pesquisas para melhor entendimento da funcao biologica dos antigenos do sistema Duffy.

Inoculation of Lacazia loboi into the subcutaneous tissue of the hamster cheek pouch

The subcutaneous tissue of the hamster cheek pouch, a site of immunologic privilege, has been used to investigate the potential infectivity of different types of parasites. It has been demonstrated that the implantation of fragments of lesions induced by the fungus Lacazia loboi, the etiologic agent of Jorge Lobo's disease, into the subcutaneous tissue of the hamster cheek pouch resulted in parasite multiplication and dissemination to satellite lymph nodes16. Here we describe the evolution of lesions induced by the inoculation of the isolated fungus into this immunologically privileged site. The morphology of the inflammatory response and fungal viability and proliferation were evaluated. Inoculation of the fungus into the cheek pouch induced histiocytic granulomas with rare lymphocytes. Although fungal cells were detected for a period of up to 180 days in these lesions, the fungi lost viability after the first day of inoculation. In contrast, when the parasite was inoculated into the footpad, non-organized histiocytic lesions were observed. Langhan's giant cells, lymphocytes and fungal particles were observed in these lesions. Fungal viability was observed up to 60 days after inoculation and non-viable parasites were present in the persistent lesions up to 180 days post-inoculation. These data indicate that the subcutaneous tissue of the hamster cheek pouch is not a suitable site for the proliferation of Lacazia loboi when the fungus isolated from human tissues is tested.